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| author | Christian König <christian.koenig@amd.com> | 2020-11-16 15:47:11 +0300 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2021-02-09 19:27:12 +0300 |
| commit | d4bd7776a7ac504510656c0053a55c0cfd1ebc96 (patch) | |
| tree | f460c3127ce0e755b6a271215e35320118aa259d /include/drm/ttm | |
| parent | 8a945edd183d296cd1125a2724fb0f3c77d8e9b3 (diff) | |
| download | linux-d4bd7776a7ac504510656c0053a55c0cfd1ebc96.tar.xz | |
drm/ttm: rework ttm_tt page limit v4
TTM implements a rather extensive accounting of allocated memory.
There are two reasons for this:
1. It tries to block userspace allocating a huge number of very small
BOs without accounting for the kmalloced memory.
2. Make sure we don't over allocate and run into an OOM situation
during swapout while trying to handle the memory shortage.
This is only partially a good idea. First of all it is perfectly
valid for an application to use all of system memory, limiting it to
50% is not really acceptable.
What we need to take care of is that the application is held
accountable for the memory it allocated. This is what control
mechanisms like memcg and the normal Linux page accounting already do.
Making sure that we don't run into an OOM situation while trying to
cope with a memory shortage is still a good idea, but this is also
not very well implemented since it means another opportunity of
recursion from the driver back into TTM.
So start to rework all of this by implementing a shrinker callback which
allows for TT object to be swapped out if necessary.
v2: Switch from limit to shrinker callback.
v3: fix gfp mask handling, use atomic for swapable_pages, add debugfs
v4: drop the extra gfp_mask checks
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210208133226.36955-1-christian.koenig@amd.com
Diffstat (limited to 'include/drm/ttm')
| -rw-r--r-- | include/drm/ttm/ttm_bo_api.h | 2 | ||||
| -rw-r--r-- | include/drm/ttm/ttm_tt.h | 6 |
2 files changed, 6 insertions, 2 deletions
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 62734db0b421..1297a8fb7ccb 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -569,7 +569,7 @@ ssize_t ttm_bo_io(struct ttm_device *bdev, struct file *filp, const char __user *wbuf, char __user *rbuf, size_t count, loff_t *f_pos, bool write); -int ttm_bo_swapout(struct ttm_operation_ctx *ctx); +int ttm_bo_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags); /** * ttm_bo_uses_embedded_gem_object - check if the given bo uses the diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h index 0020a0588985..cce57fb49e2c 100644 --- a/include/drm/ttm/ttm_tt.h +++ b/include/drm/ttm/ttm_tt.h @@ -135,7 +135,8 @@ void ttm_tt_destroy_common(struct ttm_device *bdev, struct ttm_tt *ttm); * Swap in a previously swap out ttm_tt. */ int ttm_tt_swapin(struct ttm_tt *ttm); -int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm); +int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm, + gfp_t gfp_flags); /** * ttm_tt_populate - allocate pages for a ttm @@ -155,6 +156,9 @@ int ttm_tt_populate(struct ttm_device *bdev, struct ttm_tt *ttm, struct ttm_oper */ void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm); +int ttm_tt_mgr_init(void); +void ttm_tt_mgr_fini(void); + #if IS_ENABLED(CONFIG_AGP) #include <linux/agp_backend.h> |